#include <stdio.h>
#include <windows.h>
#include <cstdint>
typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;

/* part1
typedef void (*func)();

int main(int argc, char** argv)
{
	func g = (func)VirtualAlloc(NULL, 1024, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE);
	FILE *f = fopen("./part1.bin", "rb");
	fread(g, 1, 160, f);
	fclose(f);
	f = fopen("./DecodedBase64.bin", "rb");
	fread((u8 *)g + 160, 1, 58, f);
	fclose(f);
	
	*((u16 *)((u8 *)g + 0x93)) = 0xcccc;

	g();

	return 0;
}
//*/

//* part2
#pragma pack(push, 1)
struct Opcode
{
	enum Inst
	{
		jmp, movr, movm, add, xor, cmp, jmpe, hlt
	};
	union
	{
		u8 opcode;
		struct
		{
			u8 a:4;
			u8 m:1;
			u8 op:3;
		};
	};
	u8 b;

	Opcode() { opcode = b = 0; }
	Opcode(u8 *ram)
	{
		opcode = *ram;
		if (needs2nd())
			b = *++ram;
	}

	inline bool needs2nd() { return m || !(op == jmp || op == jmpe || op == hlt); }
};
#pragma pack(pop)

static u8 ram[] = {
	0x31, 0x04, 0x33, 0xaa, 0x40, 0x02, 0x80, 0x03, 0x52, 0x00, 0x72, 0x01, 0x73, 0x01, 0xb2, 0x50,
	0x30, 0x14, 0xc0, 0x01, 0x80, 0x00, 0x10, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x98, 0xab, 0xd9, 0xa1, 0x9f, 0xa7, 0x83, 0x83, 0xf2, 0xb1, 0x34, 0xb6, 0xe4, 0xb7, 0xca, 0xb8,
	0xc9, 0xb8, 0x0e, 0xbd, 0x7d, 0x0f, 0xc0, 0xf1, 0xd9, 0x03, 0xc5, 0x3a, 0xc6, 0xc7, 0xc8, 0xc9,
	0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9,
	0xda, 0xdb, 0xa9, 0xcd, 0xdf, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
	0x26, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9,
	0x7d, 0x1f, 0x15, 0x60, 0x4d, 0x4d, 0x52, 0x7d, 0x0e, 0x27, 0x6d, 0x10, 0x6d, 0x5a, 0x06, 0x56,
	0x47, 0x14, 0x42, 0x0e, 0xb6, 0xb2, 0xb2, 0xe6, 0xeb, 0xb4, 0x83, 0x8e, 0xd7, 0xe5, 0xd4, 0xd9,
	0xc3, 0xf0, 0x80, 0x95, 0xf1, 0x82, 0x82, 0x9a, 0xbd, 0x95, 0xa4, 0x8d, 0x9a, 0x2b, 0x30, 0x69,
	0x4a, 0x69, 0x65, 0x55, 0x1c, 0x7b, 0x69, 0x1c, 0x6e, 0x04, 0x74, 0x35, 0x21, 0x26, 0x2f, 0x60,
	0x03, 0x4e, 0x37, 0x1e, 0x33, 0x54, 0x39, 0xe6, 0xba, 0xb4, 0xa2, 0xad, 0xa4, 0xc5, 0x95, 0xc8,
	0xc1, 0xe4, 0x8a, 0xec, 0xe7, 0x92, 0x8b, 0xe8, 0x81, 0xf0, 0xad, 0x98, 0xa4, 0xd0, 0xc0, 0x8d,
	0xac, 0x22, 0x52, 0x65, 0x7e, 0x27, 0x2b, 0x5a, 0x12, 0x61, 0x0a, 0x01, 0x7a, 0x6b, 0x1d, 0x67,
	0x75, 0x70, 0x6c, 0x1b, 0x11, 0x25, 0x25, 0x70, 0x7f, 0x7e, 0x67, 0x63, 0x30, 0x3c, 0x6d, 0x6a,
	0x01, 0x51, 0x59, 0x5f, 0x56, 0x13, 0x10, 0x43, 0x19, 0x18, 0xe5, 0xe0, 0xbe, 0xbf, 0xbd, 0xe9,
	0xf0, 0xf1, 0xf9, 0xfa, 0xab, 0x8f, 0xc1, 0xdf, 0xcf, 0x8d, 0xf8, 0xe7, 0xe2, 0xe9, 0x93, 0x8e,
	0xec, 0xf5, 0xc8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

	0x37, 0x7a, 0x07, 0x11, 0x1f, 0x1d, 0x68, 0x25, 0x32, 0x77, 0x1e, 0x62, 0x23, 0x5b, 0x47, 0x55,
	0x53, 0x30, 0x11, 0x42, 0xf6, 0xf1, 0xb1, 0xe6, 0xc3, 0xcc, 0xf8, 0xc5, 0xe4, 0xcc, 0xc0, 0xd3,
	0x85, 0xfd, 0x9a, 0xe3, 0xe6, 0x81, 0xb5, 0xbb, 0xd7, 0xcd, 0x87, 0xa3, 0xd3, 0x6b, 0x36, 0x6f,
	0x6f, 0x66, 0x55, 0x30, 0x16, 0x45, 0x5e, 0x09, 0x74, 0x5c, 0x3f, 0x29, 0x2b, 0x66, 0x3d, 0x0d,
	0x02, 0x30, 0x28, 0x35, 0x15, 0x09, 0x15, 0xdd, 0xec, 0xb8, 0xe2, 0xfb, 0xd8, 0xcb, 0xd8, 0xd1,
	0x8b, 0xd5, 0x82, 0xd9, 0x9a, 0xf1, 0x92, 0xab, 0xe8, 0xa6, 0xd6, 0xd0, 0x8c, 0xaa, 0xd2, 0x94,
	0xcf, 0x45, 0x46, 0x67, 0x20, 0x7d, 0x44, 0x14, 0x6b, 0x45, 0x6d, 0x54, 0x03, 0x17, 0x60, 0x62,
	0x55, 0x5a, 0x4a, 0x66, 0x61, 0x11, 0x57, 0x68, 0x75, 0x05, 0x62, 0x36, 0x7d, 0x02, 0x10, 0x4b,
	0x08, 0x22, 0x42, 0x32, 0xba, 0xe2, 0xb9, 0xe2, 0xd6, 0xb9, 0xff, 0xc3, 0xe9, 0x8a, 0x8f, 0xc1,
	0x8f, 0xe1, 0xb8, 0xa4, 0x96, 0xf1, 0x8f, 0x81, 0xb1, 0x8d, 0x89, 0xcc, 0xd4, 0x78, 0x76, 0x61,
	0x72, 0x3e, 0x37, 0x23, 0x56, 0x73, 0x71, 0x79, 0x63, 0x7c, 0x08, 0x11, 0x20, 0x69, 0x7a, 0x14,
	0x68, 0x05, 0x21, 0x1e, 0x32, 0x27, 0x59, 0xb7, 0xcf, 0xab, 0xdd, 0xd5, 0xcc, 0x97, 0x93, 0xf2,
	0xe7, 0xc0, 0xeb, 0xff, 0xe9, 0xa3, 0xbf, 0xa1, 0xab, 0x8b, 0xbb, 0x9e, 0x9e, 0x8c, 0xa0, 0xc1,
	0x9b, 0x5a, 0x2f, 0x2f, 0x4e, 0x4e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

struct Cpu
{
	enum Flags
	{
		lt = 0xff,
		gt = 1,
		eq = 0
	};

	u32 ip;
	u8 r0, r1, r2, r3,
		r4, r5; // cs, ds
	u8 fl;

	static const u32 fw[];

	Cpu()
	{
		ip = 0;
		r0 = r1 = r2 = r3 = 0;
		r4 = 0, r5 = 0x10;
		fl = 0;
	}

	Opcode readOp()
	{
		return &ram[ip];
	}

	inline u8& reg(int i)
	{
		switch (i)
		{
		case 0: return r0;
		case 1: return r1;
		case 2: return r2;
		case 3: return r3;
		case 4: return r4;
		case 5: return r5;
		}
	}

	inline u8* addr(u8 seg, u8 off)
	{
		return &ram[seg * 16 + off];
	}

	inline int offset_jmp(Opcode& o)
	{
		if (o.m)
		{
			r4 = o.b;
			return r4 * 16 + reg(o.a);
		}
		else
			return r4 * 16 + reg(o.a);
	}

	inline int reg_or_imm(Opcode& o)
	{
		if (o.m)
			return o.b;
		else
			return reg(o.b);
	}

	void run()
	{
		while (true)
		{
		next_op:
			Opcode o = readOp();

			//printf("r0 %02x r1 %02x r2 %02x r3 %02x cs %02x ds %02x ip %03x fl %02x\t",
			//	r0, r1, r2, r3, r4, r5, ip, fl);

			switch (o.op)
			{
			case o.jmp:
				printf("jmp ");
				if (o.m)
					printf("%x:", o.b);
				printf("%x\n", o.a);

				ip = offset_jmp(o);
				goto next_op;
			case o.jmpe:
				printf("jmpe ");
				if (o.m)
					printf("%x:", o.b);
				printf("r%x (%s)\n", o.a, fl == eq ? "eq" : "ne");

				if (fl == eq)
				{
					ip = offset_jmp(o);
					goto next_op;
				}
				break;

			case o.hlt:
				puts("halt");
				return;

			case o.movr:
				printf("movr r%x, %s%x\n", o.a, o.m ? "imm " : "r", o.b);

				reg(o.a) = reg_or_imm(o);
				break;
			case o.movm:
				printf("movm ");
				if (o.m)
					printf("[%x:%x], r%x\n", r5, o.a, o.b);
				else
					printf("r%x, [%x:%x]\n", o.a, r5, o.b);

				if (o.m)
					*addr(r5, reg(o.a)) = reg(o.b);
				else
					reg(o.a) = *addr(r5, reg(o.b));
				break;

			case o.add:
				printf("add r%x, %s%x\n", o.a, o.m ? "imm " : "r", o.b);
				reg(o.a) += reg_or_imm(o);
				break;
			case o.xor:
				printf("xor r%x, %s%x\n", o.a, o.m ? "imm " : "r", o.b);
				reg(o.a) ^= reg_or_imm(o);
				break;

			case o.cmp:
				printf("cmp r%x, %s%x\n", o.a, o.m ? "imm " : "r", o.b);
				{
				u8 a = reg(o.a), b = reg_or_imm(o);
				if (a > b)
					fl = gt;
				else if (a < b)
					fl = lt;
				else
					fl = eq;
				}
				break;

			default:
				printf("unk op %x\n", o.opcode);
				break;
			}

			ip = ip++ + o.needs2nd();
		}
	}
};

const u32 Cpu::fw[] = { 0xd2ab1f05, 0xda13f110 };

int main(int argc, char** argv)
{
	Cpu cpu;

	cpu.run();

	FILE *f = fopen("./datasegs.bin", "wb");
	fwrite(&ram[0x100], sizeof(ram) - 0x100, 1, f);
	fclose(f);

	return 0;
}
//*/

// part 3 uses the strange word in part1.bin and the Cpu::fw to compose a url to request the final key from. sigh, what a stupid contest...